summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/i915_gem_execbuffer.c
blob: 792c52a235eeb4cf7aee039688160bf16e21bc96 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
/*
 * Copyright © 2008,2010 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_drv.h"
#include <linux/dma_remapping.h>

struct eb_objects {
	struct list_head objects;
	int and;
	union {
		struct drm_i915_gem_object *lut[0];
		struct hlist_head buckets[0];
	};
};

static struct eb_objects *
eb_create(struct drm_i915_gem_execbuffer2 *args)
{
	struct eb_objects *eb = NULL;

	if (args->flags & I915_EXEC_HANDLE_LUT) {
		int size = args->buffer_count;
		size *= sizeof(struct drm_i915_gem_object *);
		size += sizeof(struct eb_objects);
		eb = kmalloc(size, GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
	}

	if (eb == NULL) {
		int size = args->buffer_count;
		int count = PAGE_SIZE / sizeof(struct hlist_head) / 2;
		BUILD_BUG_ON_NOT_POWER_OF_2(PAGE_SIZE / sizeof(struct hlist_head));
		while (count > 2*size)
			count >>= 1;
		eb = kzalloc(count*sizeof(struct hlist_head) +
			     sizeof(struct eb_objects),
			     GFP_TEMPORARY);
		if (eb == NULL)
			return eb;

		eb->and = count - 1;
	} else
		eb->and = -args->buffer_count;

	INIT_LIST_HEAD(&eb->objects);
	return eb;
}

static void
eb_reset(struct eb_objects *eb)
{
	if (eb->and >= 0)
		memset(eb->buckets, 0, (eb->and+1)*sizeof(struct hlist_head));
}

static int
eb_lookup_objects(struct eb_objects *eb,
		  struct drm_i915_gem_exec_object2 *exec,
		  const struct drm_i915_gem_execbuffer2 *args,
		  struct drm_file *file)
{
	int i;

	spin_lock(&file->table_lock);
	for (i = 0; i < args->buffer_count; i++) {
		struct drm_i915_gem_object *obj;

		obj = to_intel_bo(idr_find(&file->object_idr, exec[i].handle));
		if (obj == NULL) {
			spin_unlock(&file->table_lock);
			DRM_DEBUG("Invalid object handle %d at index %d\n",
				   exec[i].handle, i);
			return -ENOENT;
		}

		if (!list_empty(&obj->exec_list)) {
			spin_unlock(&file->table_lock);
			DRM_DEBUG("Object %p [handle %d, index %d] appears more than once in object list\n",
				   obj, exec[i].handle, i);
			return -EINVAL;
		}

		drm_gem_object_reference(&obj->base);
		list_add_tail(&obj->exec_list, &eb->objects);

		obj->exec_entry = &exec[i];
		if (eb->and < 0) {
			eb->lut[i] = obj;
		} else {
			uint32_t handle = args->flags & I915_EXEC_HANDLE_LUT ? i : exec[i].handle;
			obj->exec_handle = handle;
			hlist_add_head(&obj->exec_node,
				       &eb->buckets[handle & eb->and]);
		}
	}
	spin_unlock(&file->table_lock);

	return 0;
}

static struct drm_i915_gem_object *
eb_get_object(struct eb_objects *eb, unsigned long handle)
{
	if (eb->and < 0) {
		if (handle >= -eb->and)
			return NULL;
		return eb->lut[handle];
	} else {
		struct hlist_head *head;
		struct hlist_node *node;

		head = &eb->buckets[handle & eb->and];
		hlist_for_each(node, head) {
			struct drm_i915_gem_object *obj;

			obj = hlist_entry(node, struct drm_i915_gem_object, exec_node);
			if (obj->exec_handle == handle)
				return obj;
		}
		return NULL;
	}
}

static void
eb_destroy(struct eb_objects *eb)
{
	while (!list_empty(&eb->objects)) {
		struct drm_i915_gem_object *obj;

		obj = list_first_entry(&eb->objects,
				       struct drm_i915_gem_object,
				       exec_list);
		list_del_init(&obj->exec_list);
		drm_gem_object_unreference(&obj->base);
	}
	kfree(eb);
}

static inline int use_cpu_reloc(struct drm_i915_gem_object *obj)
{
	return (obj->base.write_domain == I915_GEM_DOMAIN_CPU ||
		!obj->map_and_fenceable ||
		obj->cache_level != I915_CACHE_NONE);
}

static int
relocate_entry_cpu(struct drm_i915_gem_object *obj,
		   struct drm_i915_gem_relocation_entry *reloc)
{
	uint32_t page_offset = offset_in_page(reloc->offset);
	char *vaddr;
	int ret = -EINVAL;

	ret = i915_gem_object_set_to_cpu_domain(obj, 1);
	if (ret)
		return ret;

	vaddr = kmap_atomic(i915_gem_object_get_page(obj,
				reloc->offset >> PAGE_SHIFT));
	*(uint32_t *)(vaddr + page_offset) = reloc->delta;
	kunmap_atomic(vaddr);

	return 0;
}

static int
relocate_entry_gtt(struct drm_i915_gem_object *obj,
		   struct drm_i915_gem_relocation_entry *reloc)
{
	struct drm_device *dev = obj->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	uint32_t __iomem *reloc_entry;
	void __iomem *reloc_page;
	int ret = -EINVAL;

	ret = i915_gem_object_set_to_gtt_domain(obj, true);
	if (ret)
		return ret;

	ret = i915_gem_object_put_fence(obj);
	if (ret)
		return ret;

	/* Map the page containing the relocation we're going to perform.  */
	reloc->offset += i915_gem_obj_ggtt_offset(obj);
	reloc_page = io_mapping_map_atomic_wc(dev_priv->gtt.mappable,
			reloc->offset & PAGE_MASK);
	reloc_entry = (uint32_t __iomem *)
		(reloc_page + offset_in_page(reloc->offset));
	iowrite32(reloc->delta, reloc_entry);
	io_mapping_unmap_atomic(reloc_page);

	return 0;
}

static int
i915_gem_execbuffer_relocate_entry(struct drm_i915_gem_object *obj,
				   struct eb_objects *eb,
				   struct drm_i915_gem_relocation_entry *reloc,
				   struct i915_address_space *vm)
{
	struct drm_device *dev = obj->base.dev;
	struct drm_gem_object *target_obj;
	struct drm_i915_gem_object *target_i915_obj;
	uint32_t target_offset;
	int ret = -EINVAL;

	/* we've already hold a reference to all valid objects */
	target_obj = &eb_get_object(eb, reloc->target_handle)->base;
	if (unlikely(target_obj == NULL))
		return -ENOENT;

	target_i915_obj = to_intel_bo(target_obj);
	target_offset = i915_gem_obj_ggtt_offset(target_i915_obj);

	/* Sandybridge PPGTT errata: We need a global gtt mapping for MI and
	 * pipe_control writes because the gpu doesn't properly redirect them
	 * through the ppgtt for non_secure batchbuffers. */
	if (unlikely(IS_GEN6(dev) &&
	    reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
	    !target_i915_obj->has_global_gtt_mapping)) {
		i915_gem_gtt_bind_object(target_i915_obj,
					 target_i915_obj->cache_level);
	}

	/* Validate that the target is in a valid r/w GPU domain */
	if (unlikely(reloc->write_domain & (reloc->write_domain - 1))) {
		DRM_DEBUG("reloc with multiple write domains: "
			  "obj %p target %d offset %d "
			  "read %08x write %08x",
			  obj, reloc->target_handle,
			  (int) reloc->offset,
			  reloc->read_domains,
			  reloc->write_domain);
		return ret;
	}
	if (unlikely((reloc->write_domain | reloc->read_domains)
		     & ~I915_GEM_GPU_DOMAINS)) {
		DRM_DEBUG("reloc with read/write non-GPU domains: "
			  "obj %p target %d offset %d "
			  "read %08x write %08x",
			  obj, reloc->target_handle,
			  (int) reloc->offset,
			  reloc->read_domains,
			  reloc->write_domain);
		return ret;
	}

	target_obj->pending_read_domains |= reloc->read_domains;
	target_obj->pending_write_domain |= reloc->write_domain;

	/* If the relocation already has the right value in it, no
	 * more work needs to be done.
	 */
	if (target_offset == reloc->presumed_offset)
		return 0;

	/* Check that the relocation address is valid... */
	if (unlikely(reloc->offset > obj->base.size - 4)) {
		DRM_DEBUG("Relocation beyond object bounds: "
			  "obj %p target %d offset %d size %d.\n",
			  obj, reloc->target_handle,
			  (int) reloc->offset,
			  (int) obj->base.size);
		return ret;
	}
	if (unlikely(reloc->offset & 3)) {
		DRM_DEBUG("Relocation not 4-byte aligned: "
			  "obj %p target %d offset %d.\n",
			  obj, reloc->target_handle,
			  (int) reloc->offset);
		return ret;
	}

	/* We can't wait for rendering with pagefaults disabled */
	if (obj->active && in_atomic())
		return -EFAULT;

	reloc->delta += target_offset;
	if (use_cpu_reloc(obj))
		ret = relocate_entry_cpu(obj, reloc);
	else
		ret = relocate_entry_gtt(obj, reloc);

	/* and update the user's relocation entry */
	reloc->presumed_offset = target_offset;

	return 0;
}

static int
i915_gem_execbuffer_relocate_object(struct drm_i915_gem_object *obj,
				    struct eb_objects *eb,
				    struct i915_address_space *vm)
{
#define N_RELOC(x) ((x) / sizeof(struct drm_i915_gem_relocation_entry))
	struct drm_i915_gem_relocation_entry stack_reloc[N_RELOC(512)];
	struct drm_i915_gem_relocation_entry __user *user_relocs;
	struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
	int remain, ret;

	user_relocs = to_user_ptr(entry->relocs_ptr);

	remain = entry->relocation_count;
	while (remain) {
		struct drm_i915_gem_relocation_entry *r = stack_reloc;
		int count = remain;
		if (count > ARRAY_SIZE(stack_reloc))
			count = ARRAY_SIZE(stack_reloc);
		remain -= count;

		if (__copy_from_user_inatomic(r, user_relocs, count*sizeof(r[0])))
			return -EFAULT;

		do {
			u64 offset = r->presumed_offset;

			ret = i915_gem_execbuffer_relocate_entry(obj, eb, r,
								 vm);
			if (ret)
				return ret;

			if (r->presumed_offset != offset &&
			    __copy_to_user_inatomic(&user_relocs->presumed_offset,
						    &r->presumed_offset,
						    sizeof(r->presumed_offset))) {
				return -EFAULT;
			}

			user_relocs++;
			r++;
		} while (--count);
	}

	return 0;
#undef N_RELOC
}

static int
i915_gem_execbuffer_relocate_object_slow(struct drm_i915_gem_object *obj,
					 struct eb_objects *eb,
					 struct drm_i915_gem_relocation_entry *relocs,
					 struct i915_address_space *vm)
{
	const struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
	int i, ret;

	for (i = 0; i < entry->relocation_count; i++) {
		ret = i915_gem_execbuffer_relocate_entry(obj, eb, &relocs[i],
							 vm);
		if (ret)
			return ret;
	}

	return 0;
}

static int
i915_gem_execbuffer_relocate(struct eb_objects *eb,
			     struct i915_address_space *vm)
{
	struct drm_i915_gem_object *obj;
	int ret = 0;

	/* This is the fast path and we cannot handle a pagefault whilst
	 * holding the struct mutex lest the user pass in the relocations
	 * contained within a mmaped bo. For in such a case we, the page
	 * fault handler would call i915_gem_fault() and we would try to
	 * acquire the struct mutex again. Obviously this is bad and so
	 * lockdep complains vehemently.
	 */
	pagefault_disable();
	list_for_each_entry(obj, &eb->objects, exec_list) {
		ret = i915_gem_execbuffer_relocate_object(obj, eb, vm);
		if (ret)
			break;
	}
	pagefault_enable();

	return ret;
}

#define  __EXEC_OBJECT_HAS_PIN (1<<31)
#define  __EXEC_OBJECT_HAS_FENCE (1<<30)

static int
need_reloc_mappable(struct drm_i915_gem_object *obj)
{
	struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
	return entry->relocation_count && !use_cpu_reloc(obj);
}

static int
i915_gem_execbuffer_reserve_object(struct drm_i915_gem_object *obj,
				   struct intel_ring_buffer *ring,
				   struct i915_address_space *vm,
				   bool *need_reloc)
{
	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
	struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
	bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
	bool need_fence, need_mappable;
	int ret;

	need_fence =
		has_fenced_gpu_access &&
		entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
		obj->tiling_mode != I915_TILING_NONE;
	need_mappable = need_fence || need_reloc_mappable(obj);

	ret = i915_gem_object_pin(obj, vm, entry->alignment, need_mappable,
				  false);
	if (ret)
		return ret;

	entry->flags |= __EXEC_OBJECT_HAS_PIN;

	if (has_fenced_gpu_access) {
		if (entry->flags & EXEC_OBJECT_NEEDS_FENCE) {
			ret = i915_gem_object_get_fence(obj);
			if (ret)
				return ret;

			if (i915_gem_object_pin_fence(obj))
				entry->flags |= __EXEC_OBJECT_HAS_FENCE;

			obj->pending_fenced_gpu_access = true;
		}
	}

	/* Ensure ppgtt mapping exists if needed */
	if (dev_priv->mm.aliasing_ppgtt && !obj->has_aliasing_ppgtt_mapping) {
		i915_ppgtt_bind_object(dev_priv->mm.aliasing_ppgtt,
				       obj, obj->cache_level);

		obj->has_aliasing_ppgtt_mapping = 1;
	}

	if (entry->offset != i915_gem_obj_offset(obj, vm)) {
		entry->offset = i915_gem_obj_offset(obj, vm);
		*need_reloc = true;
	}

	if (entry->flags & EXEC_OBJECT_WRITE) {
		obj->base.pending_read_domains = I915_GEM_DOMAIN_RENDER;
		obj->base.pending_write_domain = I915_GEM_DOMAIN_RENDER;
	}

	if (entry->flags & EXEC_OBJECT_NEEDS_GTT &&
	    !obj->has_global_gtt_mapping)
		i915_gem_gtt_bind_object(obj, obj->cache_level);

	return 0;
}

static void
i915_gem_execbuffer_unreserve_object(struct drm_i915_gem_object *obj)
{
	struct drm_i915_gem_exec_object2 *entry;

	if (!i915_gem_obj_bound_any(obj))
		return;

	entry = obj->exec_entry;

	if (entry->flags & __EXEC_OBJECT_HAS_FENCE)
		i915_gem_object_unpin_fence(obj);

	if (entry->flags & __EXEC_OBJECT_HAS_PIN)
		i915_gem_object_unpin(obj);

	entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
}

static int
i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
			    struct list_head *objects,
			    struct i915_address_space *vm,
			    bool *need_relocs)
{
	struct drm_i915_gem_object *obj;
	struct list_head ordered_objects;
	bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
	int retry;

	INIT_LIST_HEAD(&ordered_objects);
	while (!list_empty(objects)) {
		struct drm_i915_gem_exec_object2 *entry;
		bool need_fence, need_mappable;

		obj = list_first_entry(objects,
				       struct drm_i915_gem_object,
				       exec_list);
		entry = obj->exec_entry;

		need_fence =
			has_fenced_gpu_access &&
			entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
			obj->tiling_mode != I915_TILING_NONE;
		need_mappable = need_fence || need_reloc_mappable(obj);

		if (need_mappable)
			list_move(&obj->exec_list, &ordered_objects);
		else
			list_move_tail(&obj->exec_list, &ordered_objects);

		obj->base.pending_read_domains = I915_GEM_GPU_DOMAINS & ~I915_GEM_DOMAIN_COMMAND;
		obj->base.pending_write_domain = 0;
		obj->pending_fenced_gpu_access = false;
	}
	list_splice(&ordered_objects, objects);

	/* Attempt to pin all of the buffers into the GTT.
	 * This is done in 3 phases:
	 *
	 * 1a. Unbind all objects that do not match the GTT constraints for
	 *     the execbuffer (fenceable, mappable, alignment etc).
	 * 1b. Increment pin count for already bound objects.
	 * 2.  Bind new objects.
	 * 3.  Decrement pin count.
	 *
	 * This avoid unnecessary unbinding of later objects in order to make
	 * room for the earlier objects *unless* we need to defragment.
	 */
	retry = 0;
	do {
		int ret = 0;

		/* Unbind any ill-fitting objects or pin. */
		list_for_each_entry(obj, objects, exec_list) {
			struct drm_i915_gem_exec_object2 *entry = obj->exec_entry;
			bool need_fence, need_mappable;
			u32 obj_offset;

			if (!i915_gem_obj_bound(obj, vm))
				continue;

			obj_offset = i915_gem_obj_offset(obj, vm);
			need_fence =
				has_fenced_gpu_access &&
				entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
				obj->tiling_mode != I915_TILING_NONE;
			need_mappable = need_fence || need_reloc_mappable(obj);

			WARN_ON((need_mappable || need_fence) &&
				!i915_is_ggtt(vm));

			if ((entry->alignment &&
			     obj_offset & (entry->alignment - 1)) ||
			    (need_mappable && !obj->map_and_fenceable))
				ret = i915_vma_unbind(i915_gem_obj_to_vma(obj, vm));
			else
				ret = i915_gem_execbuffer_reserve_object(obj, ring, vm, need_relocs);
			if (ret)
				goto err;
		}

		/* Bind fresh objects */
		list_for_each_entry(obj, objects, exec_list) {
			if (i915_gem_obj_bound(obj, vm))
				continue;

			ret = i915_gem_execbuffer_reserve_object(obj, ring, vm, need_relocs);
			if (ret)
				goto err;
		}

err:		/* Decrement pin count for bound objects */
		list_for_each_entry(obj, objects, exec_list)
			i915_gem_execbuffer_unreserve_object(obj);

		if (ret != -ENOSPC || retry++)
			return ret;

		ret = i915_gem_evict_everything(ring->dev);
		if (ret)
			return ret;
	} while (1);
}

static int
i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
				  struct drm_i915_gem_execbuffer2 *args,
				  struct drm_file *file,
				  struct intel_ring_buffer *ring,
				  struct eb_objects *eb,
				  struct drm_i915_gem_exec_object2 *exec,
				  struct i915_address_space *vm)
{
	struct drm_i915_gem_relocation_entry *reloc;
	struct drm_i915_gem_object *obj;
	bool need_relocs;
	int *reloc_offset;
	int i, total, ret;
	int count = args->buffer_count;

	/* We may process another execbuffer during the unlock... */
	while (!list_empty(&eb->objects)) {
		obj = list_first_entry(&eb->objects,
				       struct drm_i915_gem_object,
				       exec_list);
		list_del_init(&obj->exec_list);
		drm_gem_object_unreference(&obj->base);
	}

	mutex_unlock(&dev->struct_mutex);

	total = 0;
	for (i = 0; i < count; i++)
		total += exec[i].relocation_count;

	reloc_offset = drm_malloc_ab(count, sizeof(*reloc_offset));
	reloc = drm_malloc_ab(total, sizeof(*reloc));
	if (reloc == NULL || reloc_offset == NULL) {
		drm_free_large(reloc);
		drm_free_large(reloc_offset);
		mutex_lock(&dev->struct_mutex);
		return -ENOMEM;
	}

	total = 0;
	for (i = 0; i < count; i++) {
		struct drm_i915_gem_relocation_entry __user *user_relocs;
		u64 invalid_offset = (u64)-1;
		int j;

		user_relocs = to_user_ptr(exec[i].relocs_ptr);

		if (copy_from_user(reloc+total, user_relocs,
				   exec[i].relocation_count * sizeof(*reloc))) {
			ret = -EFAULT;
			mutex_lock(&dev->struct_mutex);
			goto err;
		}

		/* As we do not update the known relocation offsets after
		 * relocating (due to the complexities in lock handling),
		 * we need to mark them as invalid now so that we force the
		 * relocation processing next time. Just in case the target
		 * object is evicted and then rebound into its old
		 * presumed_offset before the next execbuffer - if that
		 * happened we would make the mistake of assuming that the
		 * relocations were valid.
		 */
		for (j = 0; j < exec[i].relocation_count; j++) {
			if (copy_to_user(&user_relocs[j].presumed_offset,
					 &invalid_offset,
					 sizeof(invalid_offset))) {
				ret = -EFAULT;
				mutex_lock(&dev->struct_mutex);
				goto err;
			}
		}

		reloc_offset[i] = total;
		total += exec[i].relocation_count;
	}

	ret = i915_mutex_lock_interruptible(dev);
	if (ret) {
		mutex_lock(&dev->struct_mutex);
		goto err;
	}

	/* reacquire the objects */
	eb_reset(eb);
	ret = eb_lookup_objects(eb, exec, args, file);
	if (ret)
		goto err;

	need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
	ret = i915_gem_execbuffer_reserve(ring, &eb->objects, vm, &need_relocs);
	if (ret)
		goto err;

	list_for_each_entry(obj, &eb->objects, exec_list) {
		int offset = obj->exec_entry - exec;
		ret = i915_gem_execbuffer_relocate_object_slow(obj, eb,
							       reloc + reloc_offset[offset],
							       vm);
		if (ret)
			goto err;
	}

	/* Leave the user relocations as are, this is the painfully slow path,
	 * and we want to avoid the complication of dropping the lock whilst
	 * having buffers reserved in the aperture and so causing spurious
	 * ENOSPC for random operations.
	 */

err:
	drm_free_large(reloc);
	drm_free_large(reloc_offset);
	return ret;
}

static int
i915_gem_execbuffer_move_to_gpu(struct intel_ring_buffer *ring,
				struct list_head *objects)
{
	struct drm_i915_gem_object *obj;
	uint32_t flush_domains = 0;
	bool flush_chipset = false;
	int ret;

	list_for_each_entry(obj, objects, exec_list) {
		ret = i915_gem_object_sync(obj, ring);
		if (ret)
			return ret;

		if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
			flush_chipset |= i915_gem_clflush_object(obj, false);

		flush_domains |= obj->base.write_domain;
	}

	if (flush_chipset)
		i915_gem_chipset_flush(ring->dev);

	if (flush_domains & I915_GEM_DOMAIN_GTT)
		wmb();

	/* Unconditionally invalidate gpu caches and ensure that we do flush
	 * any residual writes from the previous batch.
	 */
	return intel_ring_invalidate_all_caches(ring);
}

static bool
i915_gem_check_execbuffer(struct drm_i915_gem_execbuffer2 *exec)
{
	if (exec->flags & __I915_EXEC_UNKNOWN_FLAGS)
		return false;

	return ((exec->batch_start_offset | exec->batch_len) & 0x7) == 0;
}

static int
validate_exec_list(struct drm_i915_gem_exec_object2 *exec,
		   int count)
{
	int i;
	int relocs_total = 0;
	int relocs_max = INT_MAX / sizeof(struct drm_i915_gem_relocation_entry);

	for (i = 0; i < count; i++) {
		char __user *ptr = to_user_ptr(exec[i].relocs_ptr);
		int length; /* limited by fault_in_pages_readable() */

		if (exec[i].flags & __EXEC_OBJECT_UNKNOWN_FLAGS)
			return -EINVAL;

		/* First check for malicious input causing overflow in
		 * the worst case where we need to allocate the entire
		 * relocation tree as a single array.
		 */
		if (exec[i].relocation_count > relocs_max - relocs_total)
			return -EINVAL;
		relocs_total += exec[i].relocation_count;

		length = exec[i].relocation_count *
			sizeof(struct drm_i915_gem_relocation_entry);
		/*
		 * We must check that the entire relocation array is safe
		 * to read, but since we may need to update the presumed
		 * offsets during execution, check for full write access.
		 */
		if (!access_ok(VERIFY_WRITE, ptr, length))
			return -EFAULT;

		if (likely(!i915_prefault_disable)) {
			if (fault_in_multipages_readable(ptr, length))
				return -EFAULT;
		}
	}

	return 0;
}

static void
i915_gem_execbuffer_move_to_active(struct list_head *objects,
				   struct i915_address_space *vm,
				   struct intel_ring_buffer *ring)
{
	struct drm_i915_gem_object *obj;

	list_for_each_entry(obj, objects, exec_list) {
		u32 old_read = obj->base.read_domains;
		u32 old_write = obj->base.write_domain;

		obj->base.write_domain = obj->base.pending_write_domain;
		if (obj->base.write_domain == 0)
			obj->base.pending_read_domains |= obj->base.read_domains;
		obj->base.read_domains = obj->base.pending_read_domains;
		obj->fenced_gpu_access = obj->pending_fenced_gpu_access;

		/* FIXME: This lookup gets fixed later <-- danvet */
		list_move_tail(&i915_gem_obj_to_vma(obj, vm)->mm_list, &vm->active_list);
		i915_gem_object_move_to_active(obj, ring);
		if (obj->base.write_domain) {
			obj->dirty = 1;
			obj->last_write_seqno = intel_ring_get_seqno(ring);
			if (obj->pin_count) /* check for potential scanout */
				intel_mark_fb_busy(obj, ring);
		}

		trace_i915_gem_object_change_domain(obj, old_read, old_write);
	}
}

static void
i915_gem_execbuffer_retire_commands(struct drm_device *dev,
				    struct drm_file *file,
				    struct intel_ring_buffer *ring,
				    struct drm_i915_gem_object *obj)
{
	/* Unconditionally force add_request to emit a full flush. */
	ring->gpu_caches_dirty = true;

	/* Add a breadcrumb for the completion of the batch buffer */
	(void)__i915_add_request(ring, file, obj, NULL);
}

static int
i915_reset_gen7_sol_offsets(struct drm_device *dev,
			    struct intel_ring_buffer *ring)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	int ret, i;

	if (!IS_GEN7(dev) || ring != &dev_priv->ring[RCS])
		return 0;

	ret = intel_ring_begin(ring, 4 * 3);
	if (ret)
		return ret;

	for (i = 0; i < 4; i++) {
		intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
		intel_ring_emit(ring, GEN7_SO_WRITE_OFFSET(i));
		intel_ring_emit(ring, 0);
	}

	intel_ring_advance(ring);

	return 0;
}

static int
i915_gem_do_execbuffer(struct drm_device *dev, void *data,
		       struct drm_file *file,
		       struct drm_i915_gem_execbuffer2 *args,
		       struct drm_i915_gem_exec_object2 *exec,
		       struct i915_address_space *vm)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct eb_objects *eb;
	struct drm_i915_gem_object *batch_obj;
	struct drm_clip_rect *cliprects = NULL;
	struct intel_ring_buffer *ring;
	u32 ctx_id = i915_execbuffer2_get_context_id(*args);
	u32 exec_start, exec_len;
	u32 mask, flags;
	int ret, mode, i;
	bool need_relocs;

	if (!i915_gem_check_execbuffer(args))
		return -EINVAL;

	ret = validate_exec_list(exec, args->buffer_count);
	if (ret)
		return ret;

	flags = 0;
	if (args->flags & I915_EXEC_SECURE) {
		if (!file->is_master || !capable(CAP_SYS_ADMIN))
		    return -EPERM;

		flags |= I915_DISPATCH_SECURE;
	}
	if (args->flags & I915_EXEC_IS_PINNED)
		flags |= I915_DISPATCH_PINNED;

	switch (args->flags & I915_EXEC_RING_MASK) {
	case I915_EXEC_DEFAULT:
	case I915_EXEC_RENDER:
		ring = &dev_priv->ring[RCS];
		break;
	case I915_EXEC_BSD:
		ring = &dev_priv->ring[VCS];
		if (ctx_id != DEFAULT_CONTEXT_ID) {
			DRM_DEBUG("Ring %s doesn't support contexts\n",
				  ring->name);
			return -EPERM;
		}
		break;
	case I915_EXEC_BLT:
		ring = &dev_priv->ring[BCS];
		if (ctx_id != DEFAULT_CONTEXT_ID) {
			DRM_DEBUG("Ring %s doesn't support contexts\n",
				  ring->name);
			return -EPERM;
		}
		break;
	case I915_EXEC_VEBOX:
		ring = &dev_priv->ring[VECS];
		if (ctx_id != DEFAULT_CONTEXT_ID) {
			DRM_DEBUG("Ring %s doesn't support contexts\n",
				  ring->name);
			return -EPERM;
		}
		break;

	default:
		DRM_DEBUG("execbuf with unknown ring: %d\n",
			  (int)(args->flags & I915_EXEC_RING_MASK));
		return -EINVAL;
	}
	if (!intel_ring_initialized(ring)) {
		DRM_DEBUG("execbuf with invalid ring: %d\n",
			  (int)(args->flags & I915_EXEC_RING_MASK));
		return -EINVAL;
	}

	mode = args->flags & I915_EXEC_CONSTANTS_MASK;
	mask = I915_EXEC_CONSTANTS_MASK;
	switch (mode) {
	case I915_EXEC_CONSTANTS_REL_GENERAL:
	case I915_EXEC_CONSTANTS_ABSOLUTE:
	case I915_EXEC_CONSTANTS_REL_SURFACE:
		if (ring == &dev_priv->ring[RCS] &&
		    mode != dev_priv->relative_constants_mode) {
			if (INTEL_INFO(dev)->gen < 4)
				return -EINVAL;

			if (INTEL_INFO(dev)->gen > 5 &&
			    mode == I915_EXEC_CONSTANTS_REL_SURFACE)
				return -EINVAL;

			/* The HW changed the meaning on this bit on gen6 */
			if (INTEL_INFO(dev)->gen >= 6)
				mask &= ~I915_EXEC_CONSTANTS_REL_SURFACE;
		}
		break;
	default:
		DRM_DEBUG("execbuf with unknown constants: %d\n", mode);
		return -EINVAL;
	}

	if (args->buffer_count < 1) {
		DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
		return -EINVAL;
	}

	if (args->num_cliprects != 0) {
		if (ring != &dev_priv->ring[RCS]) {
			DRM_DEBUG("clip rectangles are only valid with the render ring\n");
			return -EINVAL;
		}

		if (INTEL_INFO(dev)->gen >= 5) {
			DRM_DEBUG("clip rectangles are only valid on pre-gen5\n");
			return -EINVAL;
		}

		if (args->num_cliprects > UINT_MAX / sizeof(*cliprects)) {
			DRM_DEBUG("execbuf with %u cliprects\n",
				  args->num_cliprects);
			return -EINVAL;
		}

		cliprects = kmalloc(args->num_cliprects * sizeof(*cliprects),
				    GFP_KERNEL);
		if (cliprects == NULL) {
			ret = -ENOMEM;
			goto pre_mutex_err;
		}

		if (copy_from_user(cliprects,
				   to_user_ptr(args->cliprects_ptr),
				   sizeof(*cliprects)*args->num_cliprects)) {
			ret = -EFAULT;
			goto pre_mutex_err;
		}
	}

	ret = i915_mutex_lock_interruptible(dev);
	if (ret)
		goto pre_mutex_err;

	if (dev_priv->ums.mm_suspended) {
		mutex_unlock(&dev->struct_mutex);
		ret = -EBUSY;
		goto pre_mutex_err;
	}

	eb = eb_create(args);
	if (eb == NULL) {
		mutex_unlock(&dev->struct_mutex);
		ret = -ENOMEM;
		goto pre_mutex_err;
	}

	/* Look up object handles */
	ret = eb_lookup_objects(eb, exec, args, file);
	if (ret)
		goto err;

	/* take note of the batch buffer before we might reorder the lists */
	batch_obj = list_entry(eb->objects.prev,
			       struct drm_i915_gem_object,
			       exec_list);

	/* Move the objects en-masse into the GTT, evicting if necessary. */
	need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
	ret = i915_gem_execbuffer_reserve(ring, &eb->objects, vm, &need_relocs);
	if (ret)
		goto err;

	/* The objects are in their final locations, apply the relocations. */
	if (need_relocs)
		ret = i915_gem_execbuffer_relocate(eb, vm);
	if (ret) {
		if (ret == -EFAULT) {
			ret = i915_gem_execbuffer_relocate_slow(dev, args, file, ring,
								eb, exec, vm);
			BUG_ON(!mutex_is_locked(&dev->struct_mutex));
		}
		if (ret)
			goto err;
	}

	/* Set the pending read domains for the batch buffer to COMMAND */
	if (batch_obj->base.pending_write_domain) {
		DRM_DEBUG("Attempting to use self-modifying batch buffer\n");
		ret = -EINVAL;
		goto err;
	}
	batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;

	/* snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
	 * batch" bit. Hence we need to pin secure batches into the global gtt.
	 * hsw should have this fixed, but let's be paranoid and do it
	 * unconditionally for now. */
	if (flags & I915_DISPATCH_SECURE && !batch_obj->has_global_gtt_mapping)
		i915_gem_gtt_bind_object(batch_obj, batch_obj->cache_level);

	ret = i915_gem_execbuffer_move_to_gpu(ring, &eb->objects);
	if (ret)
		goto err;

	ret = i915_switch_context(ring, file, ctx_id);
	if (ret)
		goto err;

	if (ring == &dev_priv->ring[RCS] &&
	    mode != dev_priv->relative_constants_mode) {
		ret = intel_ring_begin(ring, 4);
		if (ret)
				goto err;

		intel_ring_emit(ring, MI_NOOP);
		intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
		intel_ring_emit(ring, INSTPM);
		intel_ring_emit(ring, mask << 16 | mode);
		intel_ring_advance(ring);

		dev_priv->relative_constants_mode = mode;
	}

	if (args->flags & I915_EXEC_GEN7_SOL_RESET) {
		ret = i915_reset_gen7_sol_offsets(dev, ring);
		if (ret)
			goto err;
	}

	exec_start = i915_gem_obj_offset(batch_obj, vm) +
		args->batch_start_offset;
	exec_len = args->batch_len;
	if (cliprects) {
		for (i = 0; i < args->num_cliprects; i++) {
			ret = i915_emit_box(dev, &cliprects[i],
					    args->DR1, args->DR4);
			if (ret)
				goto err;

			ret = ring->dispatch_execbuffer(ring,
							exec_start, exec_len,
							flags);
			if (ret)
				goto err;
		}
	} else {
		ret = ring->dispatch_execbuffer(ring,
						exec_start, exec_len,
						flags);
		if (ret)
			goto err;
	}

	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);

	i915_gem_execbuffer_move_to_active(&eb->objects, vm, ring);
	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);

err:
	eb_destroy(eb);

	mutex_unlock(&dev->struct_mutex);

pre_mutex_err:
	kfree(cliprects);
	return ret;
}

/*
 * Legacy execbuffer just creates an exec2 list from the original exec object
 * list array and passes it to the real function.
 */
int
i915_gem_execbuffer(struct drm_device *dev, void *data,
		    struct drm_file *file)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_i915_gem_execbuffer *args = data;
	struct drm_i915_gem_execbuffer2 exec2;
	struct drm_i915_gem_exec_object *exec_list = NULL;
	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
	int ret, i;

	if (args->buffer_count < 1) {
		DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count);
		return -EINVAL;
	}

	/* Copy in the exec list from userland */
	exec_list = drm_malloc_ab(sizeof(*exec_list), args->buffer_count);
	exec2_list = drm_malloc_ab(sizeof(*exec2_list), args->buffer_count);
	if (exec_list == NULL || exec2_list == NULL) {
		DRM_DEBUG("Failed to allocate exec list for %d buffers\n",
			  args->buffer_count);
		drm_free_large(exec_list);
		drm_free_large(exec2_list);
		return -ENOMEM;
	}
	ret = copy_from_user(exec_list,
			     to_user_ptr(args->buffers_ptr),
			     sizeof(*exec_list) * args->buffer_count);
	if (ret != 0) {
		DRM_DEBUG("copy %d exec entries failed %d\n",
			  args->buffer_count, ret);
		drm_free_large(exec_list);
		drm_free_large(exec2_list);
		return -EFAULT;
	}

	for (i = 0; i < args->buffer_count; i++) {
		exec2_list[i].handle = exec_list[i].handle;
		exec2_list[i].relocation_count = exec_list[i].relocation_count;
		exec2_list[i].relocs_ptr = exec_list[i].relocs_ptr;
		exec2_list[i].alignment = exec_list[i].alignment;
		exec2_list[i].offset = exec_list[i].offset;
		if (INTEL_INFO(dev)->gen < 4)
			exec2_list[i].flags = EXEC_OBJECT_NEEDS_FENCE;
		else
			exec2_list[i].flags = 0;
	}

	exec2.buffers_ptr = args->buffers_ptr;
	exec2.buffer_count = args->buffer_count;
	exec2.batch_start_offset = args->batch_start_offset;
	exec2.batch_len = args->batch_len;
	exec2.DR1 = args->DR1;
	exec2.DR4 = args->DR4;
	exec2.num_cliprects = args->num_cliprects;
	exec2.cliprects_ptr = args->cliprects_ptr;
	exec2.flags = I915_EXEC_RENDER;
	i915_execbuffer2_set_context_id(exec2, 0);

	ret = i915_gem_do_execbuffer(dev, data, file, &exec2, exec2_list,
				     &dev_priv->gtt.base);
	if (!ret) {
		/* Copy the new buffer offsets back to the user's exec list. */
		for (i = 0; i < args->buffer_count; i++)
			exec_list[i].offset = exec2_list[i].offset;
		/* ... and back out to userspace */
		ret = copy_to_user(to_user_ptr(args->buffers_ptr),
				   exec_list,
				   sizeof(*exec_list) * args->buffer_count);
		if (ret) {
			ret = -EFAULT;
			DRM_DEBUG("failed to copy %d exec entries "
				  "back to user (%d)\n",
				  args->buffer_count, ret);
		}
	}

	drm_free_large(exec_list);
	drm_free_large(exec2_list);
	return ret;
}

int
i915_gem_execbuffer2(struct drm_device *dev, void *data,
		     struct drm_file *file)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct drm_i915_gem_execbuffer2 *args = data;
	struct drm_i915_gem_exec_object2 *exec2_list = NULL;
	int ret;

	if (args->buffer_count < 1 ||
	    args->buffer_count > UINT_MAX / sizeof(*exec2_list)) {
		DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count);
		return -EINVAL;
	}

	exec2_list = kmalloc(sizeof(*exec2_list)*args->buffer_count,
			     GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
	if (exec2_list == NULL)
		exec2_list = drm_malloc_ab(sizeof(*exec2_list),
					   args->buffer_count);
	if (exec2_list == NULL) {
		DRM_DEBUG("Failed to allocate exec list for %d buffers\n",
			  args->buffer_count);
		return -ENOMEM;
	}
	ret = copy_from_user(exec2_list,
			     to_user_ptr(args->buffers_ptr),
			     sizeof(*exec2_list) * args->buffer_count);
	if (ret != 0) {
		DRM_DEBUG("copy %d exec entries failed %d\n",
			  args->buffer_count, ret);
		drm_free_large(exec2_list);
		return -EFAULT;
	}

	ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list,
				     &dev_priv->gtt.base);
	if (!ret) {
		/* Copy the new buffer offsets back to the user's exec list. */
		ret = copy_to_user(to_user_ptr(args->buffers_ptr),
				   exec2_list,
				   sizeof(*exec2_list) * args->buffer_count);
		if (ret) {
			ret = -EFAULT;
			DRM_DEBUG("failed to copy %d exec entries "
				  "back to user (%d)\n",
				  args->buffer_count, ret);
		}
	}

	drm_free_large(exec2_list);
	return ret;
}